1. Field of the Invention
The present invention relates to an image-forming material and a process for forming images. More particularly, it is concerned with an image-forming material and a process for forming images which will be used to make negative-positive type second originals (intermediate, transparent sheets on which original drawings are duplicated) for an editorial drawing or a composite drawing in the field of surveying.
2. Related Art Statement
There have been known image-forming materials and development processes for the production of negative-positive type second originals for an editorial drawing or a composite drawing to be used in the field of surveying.
For example, Japanese Patent Laid-open No. 91419/1977 teaches a photosensitive film where photopolymer of polyvinylalcohol partly denaturated with aromatic azido is coated on polyester film having sand matte surface. The photosensitive film undergoes negative exposure through an original and subsequent development with an alkaline aqueous solution, dyeing and washing for the formation of a positive relief image.
The above-mentioned conventional image-forming processes have an advantage of being capable of forming a colored positive relief image of the original drawing on a roughened plastic film substrate. However, they also have the disadvantage that the step of dyeing a positive relief image in the development process stains the operator's body and clothing and the working environment with the dye solution used in that step. This problem has been alleviated by the introduction of automatic development. This poses another problem associated with the maintenance of the automatic developing machine and the disposal of the dye waste liquid discharged from the automatic developing machine.
The second originals in the field of surveying sometimes have a color other than black, i.e. red, sepia, green or blue, to enable classification of the surveying drawings or to distinguish between added lines and originals. Accordingly, the aforementioned method including dyeing, a plurality of dye solutions for each color are required for making positive reliefs of various. As the result, a plurality of positive reliefs of different colors can not be formed at the same time using one automatic developing machine.
To address this problem, there has been proposed a method for forming a colored positive relief image without using a dye solution in the development process in Japanese Patent Laid-open No. 166946/1984.
This method consists of forming a colored photosensitive layer (containing a dye or pigment in a photopolymer of polyvinylalcohol, partially denaturated with substance combining styrylquinolinium or styrylpyridinium), on a polyester film substrate, exposing the photosensitive material for negative printing of the original, and forming a colored positive relief image by development with water.
This method obviates the use of a dye solution in the development process. A disadvantage of this method is that the photosensitive resin layer must contain a large amount of coloring component. Increasing the amount of the coloring component greatly lowers the printing sensitivity of the photosensitive resin layer, which must be compensated for by a large amount of exposure in negative printing of the original.
Moreover, when the photosensitive colored resin layer is coated on the roughened film, it tends to cause base fogging of non-imaged area due to the sticking of a dye or pigment (from the photosensitive colored resin layer) to the roughened polyester film.